Gerry Adams is expected to set out a timetable for his departure that will take about a year.
Photograph: Will Oliver/EPA

Gerry Adams will announce his plans to retire after 34 years as president of Sinn Féin on Saturday, marking a generational shift that will break the leadership’s last link with republican violence.

Adams will take to the stage of Dublin’s RDS conference hall to set out an exit that some analysts say will improve Sinn Féin’s electoral chances in the Irish Republic.

But sources within the mainstream Irish republican movement and veteran Adams-watchers believe the 69-year-old will still hold the centre of power in Sinn Féin from behind the scenes long after his official successor is elevated to the top post.

Having survived as head of his party longer than five British prime ministers, six Irish premiers and five US presidents, Adams will use the televised speech to set out a timetable for his departure that he has indicated will take about a year.

When he does finally go, the Sinn Féin politician most likely to take over from Adams will be the party’s deputy leader and Dublin TD, Mary Lou McDonald. With Michelle O’Neill the leader in Northern Ireland, the party once umbilically linked to the Provisional IRA and its armed campaign will not only be led by two women but also by a generation with no direct involvement in the Provisionals’ 30-year “war”.

One veteran of the IRA’s West Belfast Brigade who was once close to Adams and his family doubts that the former MP for the constituency and TD for Louth in the Irish Republic is about to relinquish his full control of the party.

“Gerry made Sinn Féin in his own image,” the former IRA prisoner said.

“Whatever you think about him he was the master strategist. He built Sinn Féin up into an efficient electoral machine. He guided the party and the movement away from war to peace. It could never have been done without him and he knows that. He still thinks he can push them on to power in the south [Irish Republic] as his final achievement. So he will be staying around, in the back room, working the controls.”

Outside observers of the often closed world of Irish republicanism also agree that Adams’s history and character dictate he will still play a leading role behind the scenes.

Deaglán de Bréadún, the author of Power Play: The Rise of Modern Sinn Féin, said: “It is hard to imagine him withdrawing entirely from political activity.”

Although he has a certain popular appeal as an icon of Irish republicanism, the more controversial aspects of his past are constantly highlighted by political opponents in the Republic.

On Adams’s switch from Northern Ireland to the Dáil, De Bréadún noted: “He has never really settled into the political scene in the Republic and his grasp of the finer points of economic policy, for example, remains rather limited.

“Nor does he appear to enjoy the cut and thrust of parliamentary debate.”

Gerry Adams with the Sinn Féin deputy leader, Mary Lou McDonald, who is tipped as the candidate most likely to succeed him as leader. Photograph: Niall Carson/PA

There was speculation that Adams would use his semi-retirement to run next year for the presidency of Ireland. Last weekend, however, he ruled himself out of a contest that proved to be particularly brutal and bruising for McGuinness back in 2011.

On the hustings McGuinness came face to face with IRA victims, including the son of an Irish soldier the Provisionals had murdered who said in front of the TV cameras that the Sinn Féin deputy leader was not fit to be president of the nation.

Adams’s unofficial biographer, however, believes the Sinn Féin president will impose one cast-iron rule on his replacement – a vigorous defence at all times of the legitimacy of the Provisional IRA’s campaign.

“He will not want or allow any successor to ever cast doubt on the validity of that IRA campaign. He will want them to state that this campaign was as legitimate as the rebels of 1916.”

Despite his many remarkable achievements in turning the republican movement towards solely peaceful constitutional politics, Adams is now seen by both external observers and some party insiders as a brake on the party’s growth in the Republic.

His longstanding connection to the IRA’s violent “armed struggle” and his often poor performances in Dáil parliamentary debates continue to alienate vast sections of the Irish Republic’s middle class.

Yet despite his promise before this weekend’s 2017 Sinn Féin Ard Fheis to provide a road map to retirement, Adams the author as much as the leader continues to leave hints about his true intentions. Earlier this month he launched a new book, a collection of his writings on topics ranging from his thoughts on Brexit to his love of dogs. Adams’s latest work is titled Never Give Up.

Gerry Adams

1970

Adams joins up with the Provisionals after the IRA divided with the Marxist Officials.

1972

He is interned without trial in Long Kesh prison camp as an IRA suspect, but freed that summer to join an IRA delegation that held secret meetings with British ministers in London.

1973-76

Adams is imprisoned several times and starts to write under the nom de guerre of Brownie for the republican newspaper An Phoblacht, mapping out a political strategy beyond the IRA’s armed campaign.

1981

While Sinn Féin’s vice-president he plays a pivotal role in the hunger strikes in which seven IRA prisoners and three INLA inmates starve themselves to death for political status. The mass support on the streets for the hunger strikers convinces Adams of the need to engage in electoral politics.

1983

Adams is elected MP for West Belfast and later internally voted in as Sinn Féin president, a post he has held ever since.

1984

He is shot and wounded by a UDA assassin in central Belfast.

1992

He loses his West Belfast seat to the moderate nationalist party the SDLP as talks are about to start between him and John Hume, its leader.

1994

Adams is one of the co-architects alongside McGuinness of an IRA ceasefire, which within three years becomes a permanent cessation of violence.

1997

He sees off an attempted coup d’etat by a hardline IRA faction to take over the republican movement and push it towards war once more. The defeated recalcitrants break away to form the Real IRA.

1998

2005

The IRA decommissions most of its huge terror arsenal.

2007

Adams backs McGuinness to enter a power-sharing government with their former foe the Rev Ian Paisley – a once unthinkable arrangement that leads to almost a decade of a devolved cross-community coalition in Northern Ireland. Adams’s ultimate aim of a united Ireland, however, has failed to materialise and is unlikely to in his lifetime.